湖北神农架地区南华系大塘坡组元素地球化学特征.

Datangpo Formation of Nanhua System in Shennongjia area of Hubei belongs to interglacial deposit, and the understanding of its sedimentary strata and paleoenvironment is limited at present. Based on the field geological investigation of Datangpo Formation of Nanhua System in Shennongjia area, the paleoenvironmental characteristics of Datangpo Formation and their significance for oil and gas exploration in this area were systematically studied by using the data of element geochemistry analysis. The ratios of CaO/(CaO+Fe), Sr/Ba, Rb/K, K/Na indicate that the sedimentary water salinity of Datangpo Formation is low-medium, and the sedimentary water salinity in the Dajiuhu section is higher than that in the Songluo section. Based on the relevant parameters of oxidation-reduction sensitive elements including the ratios of V/(V+Ni)and Ni/Co, and Ceanom, the results show that Datangpo Formation of Nanhua System in Shennongjia area deposits in a weak oxidation-weak reduction water environment. The CIA, ICV, ratios of Sr/Cu, Sr/Ba, Rb/Sr and Mg/Ca, and the content of Sr indicate that the paleoclimate of Datangpo Formation during the deposition period is a warm and humid climate. Comprehensive analyses of TOC, paleontology and the contents of Cu and Ba show that the warm and humid climate, and water conditions during the deposition period of Datangpo Formation are very suitable for the mass reproduction of aquatic algae, and provide sufficient organic matters for the high-quality source rocks of Datangpo Formation. [ABSTRACT FROM AUTHOR]